Amount of data stored in a storage apparatus is increasing every year. Since the storage apparatus stores mass data, the storage apparatus is equipped with many physical storage devices, and a storage controller (hereinafter, ST-CL) controls read/write of the data to a storage device (TO processing). The ST-CTL, for example, controls the physical storage devices, such as SSDs (Solid State Drives) and HDDs (Hard Disk Drives), as RAID groups, and provides a volume which is logical storage space to a host computer (hereinafter, host). Although the ST-CTL provides a host with multiple volumes, the capacity of each volume is also increasing with increase of data volume.
In the storage apparatus, for example, disaster recovery and/or failure processing, the duplicate of volume is created. And the ST-CTL copies the data, stored in one or more physical storage devices which constitute a volume and the duplicate of the volume, within a physical storage device and/or between physical storage devices.
For example, in a data copy process between physical devices, the ST-CTL, which is a higher-level apparatus with respect to the physical storage device, for example, reads copy-target data (hereinafter, target data) from the physical storage device of the copy source in accordance with an indication from the host, stores the read target data in a cache memory controlled by the ST-CTL, and writes the target data, which has been stored in the cache memory, to the physical storage device of the copy destination (for example, refer to Patent Literature 1).